Polymer Chemistry
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2015
·Vol. 6
·期 15
·2892-2899
·
IF 5.52
Shuai Xu,Zhihuan Weng,Jing Tan,Jia Guo,Changchun Wang
We present the preparation of nanoscale porous organic polymer (POP) composite microspheres consisting of an Fe3O4 supraparticle as the core and micro-/mesoporous POP as the shell. The core/shell-structured Fe3O4@PS microspheres were synthesized, and then subjected to a seeded swelling polymerization in the PS shell using a mixture of divinyl benzene (DVB) and vinylbenzene chloride (VBC). The formed poly(VBC-co-DVB) networks were blended with PS in the shell, resulting in a distinct phase segregation. Upon a Friedel–Craft-type hyper-crosslinking treatment, the POP structure was obtained showing the specific porosity. During this process, the non-crosslinking PS chains were extracted out of the shell and large-sized mesopores were achieved with the micropores obtained by the hyper-crosslinking networks. By varying the feed amount of VBC and DVB, the phase segregation was changed and the prevailing mesopores could be tuned from 4 nm to 30 nm. The contribution of micropores to the entire porosity was accordingly altered. In light of the characteristics of dual-level pores and magnetic recyclability, the Pt nanoparticles were locally reduced within the mesopores, and the reactive substrates were then accessible to microporous zones in the POP shell. The enantioselective hydrogenation of ethyl pyruvate was applied to evaluate the catalytic activity of the Fe3O4@POP/Pt composites. Under optimized conditions (20 bar H2 pressure, 20 h, R.T. and molar ratio of Pt/CD: 6/1), the Fe3O4@POP/Pt composite catalysts containing 10 wt% Pt nanoparticles were validated to have excellent catalytic activity, outstanding reusability, and a high product yield and ee value (80.7%) for the enantioselective conversion of ethyl pyruvate to ethyl lactate.
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JOURNAL OF FOOD SCIENCE
·
2015
·Vol. 80
·期 11
·C2452
·
IF 1.696
Juan Wang,Lei Zhang,Dingqiang Xin,Yaling Yang
en This link goes to a English section pt This link goes to a English section A novel, simple and low cost through coating Fe 3 O 4 magnetic nanoparticles (MNPs) with decanoic acid were synthesized. The functionalized MNPs showed excellent dispersibility in aqueous solution and were applied to dispersive micro-solid-phase extraction (D-μ-SPE) followed by high performance liquid chromatographic analysis for 4 phthalate esters (PAEs) including benzyl butyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di-n-butyl phthalate (DBP), and di-n-octyl phthalate (DNOP) from liquor samples. The extraction equilibrium is achieved in 1 min. The MNPs allow easy and rapid isolation of PAEs by using an external magnet, which can be reused 5 times. The 4 PAEs linear dynamic ranges were in the range of 5 to 1000 ng/mL and the correlation coefficients values were 0.9999. The limits of detection were in the range of 0.91 to 2.43 ng/mL. The influences of the adsorbent dosage and the use frequency of adsorbent, the adsorption time, the solution pH and ionic strength were investigated and optimized. The proposed method was used to determine of PAEs in liquor samples and recoveries between 88.9% and 105.4%, with the relative standard deviations were below 4.0%. Practical Application en This link goes to a English section pt This link goes to a English section The results from this study can attract the attention of countries in control of liquors’ quality.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2015
·
IF 2.912
Jie Long,Zhengzong Wu,Xingfei Li,Enbo Xu,Xueming Xu,Zhengyu Jin,Aiquan Jiao
We present a simple method to immobilize pullulanase onto hybrid magnetic (Fe3O4–κ-carrageenan) nanoparticles, involving the in situ synthesis of magnetic carrageenan nanoparticles and the formation of pullulanase/chitosan complex. The complex behavior of pullulanase with chitosan as a function of pH and protein–polysaccharide ratio was studied by turbidimetric titration. Then, the as-prepared immobilized enzymes were characterized by vibrating-sample magnetometer, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffractometer, and thermogravimetric analysis. It was found that the activity retention of immobilized pullulanase and amount of enzyme loaded reached 95.5% and 96.3 mg/g, respectively, under optimal conditions. The immobilized enzyme exhibited great operational stability (retaining approximately 61% residual activity after ten consecutive reuses), demonstrating that enzyme leakage during the catalysis reaction was efficiently reduced. Furthermore, the activity of immobilized pullulanase was significantly (p < 0.01) higher than that of free pullulanase in a low pH range (pH < 3.0) and temperature over 60 °C, and the immobilized enzymes retained 45% of their initial activity after 5 h at 60 °C, compared to 21% for the free enzyme. These results indicated that immobilized pullulanase was efficient in terms of catalytic activity and can be applied to continuous starch processing applications in the food industry.
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Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 33
·13471-13478
·
IF 0
Yunfeng Qiu,Zhuo Ma,PingAn Hu
We report the facile synthesis of environmentally benign Au NPs/chitosan composites and magnetic Au NPs/chitosan/Fe3O4 composites without employing any toxic reductants or capping agents. Renewable natural chitosan not only functioned as supporting matrix, but also served as a reductant and stabilizer for the formation and dispersions of Au NPs. Fe3O4 nanospheres were easily embedded into the chitosan matrix due to the strong complexation ability of chitosan with Fe3O4, which originated from the sharing of the lone electron pairs from the nitrogen atom in amine with FeII or FeIII on the surface of Fe3O4. The as-prepared magnetic composites exhibited much higher activities, as well as more convenient magnetic recyclability than other supported Au NPs towards the reduction of 4-nitrophenol. From the practical point of view, apart from good performance of the reduction of nitro compounds, the biocompatibility and biodegradability of present Au NPs/chitosan/Fe3O4 composites promote the potential applications in the biochemical catalysis or therapy.
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Journal of Materials Chemistry B
·
2014
·Vol. 2
·期 35
·5775-5784
·
IF 0
Song Shen,Xiaomeng Guo,Lin Wu,Meng Wang,Xinshi Wang,Fenfen Kong,Haijun Shen,Meng Xie,Yanru Ge,Yi Jin
Multifunctional dual-core@shell (Fe3O4–NaYF4@TiO2) nanocomposite (DCSNC) loaded with doxorubicin (DOX) have been developed for synergetic sonodynamic cancer chemotherapy, where titanium dioxide (TiO2) is employed as a sonosensitizer for sonodynamic therapy (SDT) of the tumor in deep tissues, and NaYF4 is used for upconversion luminescence (UCL) imaging. After being coated with hyaluronic acid (HA), the nanocomposites exhibit a time dependent cellular uptake and an excellent nucleus targeting effect in KB and MCF-7 cells. The ultrasound of HA–DCSNCs obviously enhances the apoptosis rate of MCF-7 cells. A greater tumor inhibition rate is observed when the tumor-bearing mice are treated with combined therapy (88.36%) compared with chemotherapy (28.36%) or sonodynamic therapy (38.91%) alone, indicating the potential of sonodynamic chemotherapy for cancer treatment.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2016
·
IF 8.328
Lei Tan,Shaoyou Lu,Zhanqiang Fang,Wen Cheng,Eric Pokeung Tsang
The magnetic Fe 0 @Fe 3 O 4 nanocomposite was prepared and used to achieve the reductive/subsequent oxidative ring-opening of decabromodiphenyl ether (BDE209) in this work. The characterization results indicated that the structure of the composite consisted of small nanoscale zero-valent iron (nZVI) particles surrounding the surface of Fe 3 O 4 nanoparticle (NP). A 100% removal efficiency and 80% degradation efficiency of BDE209 was reached by the composite accompanied with ultrasound(called NP/US system) for 36 h, which is higher than that obtained with conventional nZVI particles. Furthermore, the enhanced debromination and ring-opening of BDE209 was realized by a Fenton-like degradation process lasting for 12 h after the addition of H 2 O 2 to the NP/US reaction at 36 h. Based on the degradation products identified, a two-stage reduction/oxidation degradation mechanism was proposed. During the first stage, which was reductive debromination, the major reductive activity of nZVI was efficiently enhanced in the presence of nano Fe 3 O 4 , which served as a catalyst to improve the stability of the nZVI nanoparticles and accelerate electron transfer, enhancing the degradation efficiency of BDE209. During the second stage, the oxidative ring-opening, the debromination products of BDE209 were proved to be attacked by abundant hydroxyl radicals generated both in the solution and on the surface of the Fe 0 @Fe 3 O 4 nanoparticles. Thus, this work provides an efficient method to achieve the complete ring-opening of PBDEs using iron-based nanomaterials.
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MICROPOROUS AND MESOPOROUS MATERIALS
·
2016
·
IF 3.349
Yan Liu,Jian Qiu,Yinhua Jiang,Zhanchao Liu,Minjia Meng,Liang Ni,Changchun Qin,Jianbo Peng
Ce(III) ion-imprinted polymer (Ce(III)-IIP) grafted on Fe 3 O 4 nanoparticles supported by SBA-15 mesopores microreactor was successfully synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization for selective removal of Ce(III) from aqueous solution. The characterization results suggest that the surface ion-imprinted polymer (IIP) synthesized by RAFT is a thin layer. Adsorption isotherm experiments indicated that Redlich-Peterson isotherm model best fitted the experimental data and the adsorption capacity of IIP was obviously higher than that of non-imprinted polymers (NIP) at the same conditions. The kinetics of adsorption followed the Thomas model. Moreover, competitive adsorption studies illustrated that Ce(III)-IIP offers the advantages of selectivity towards Ce(III) compared with NIP even in the presence of other metal ions. All above results indicated the potential application of Ce(III)-IIP for selective removal of Ce(III) from aqueous solution.
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ANALYTICA CHIMICA ACTA
·
2016
·
IF 4.712
Xiaoling Yang,Kexin Qiao,Yiren Ye,Miyi Yang,Jing Li,Haixiang Gao,Sanbing Zhang,Wenfeng Zhou,Runhua Lu
In this study, the superparamagnetic attapulgite/Fe 3 O 4 /polyaniline (ATP/Fe 3 O 4 /PANI) nanocomposites were successfully synthesized by a one-pot method. Fe (III) was applied as both the oxidant for the oxidative polymerization of aniline and the single iron source of Fe 3 O 4 formed by the redox reaction between aniline and Fe (III). The ATP/Fe 3 O 4 /PANI was used as sorbent for magnetic dispersive solid phase extraction (MDSPE) of benzoylurea insecticides (BUs) in environmental water samples. The as-prepared nanocomposite sorbents were characterized by Fourier transform infrared spectra (FT-IR), X Ray diffraction (XRD), scanning electron microscopy(SEM), transmission electron microscopy (TEM), and vibrating sample magnetometry . Various experimental parameters affecting the ATP/Fe 3 O 4 /PANI-based MDSPE procedure, including the composition of the nanocomposite sorbents, amount of ATP/Fe 3 O 4 /PANI nanocomposites, vortex time, pH, and desorption conditions were investigated. Under the optimal conditions, a good linearity was observed for all target analytes, with correlation coefficients (r 2 ) ranging from 0.9985 to 0.9997; the limits of detection (LOD) were in the range of 0.02–0.43 μg L −1 , and the recoveries of analytes using the proposed method ranged between 77.37% and 103.69%. The sorbents exhibited an excellent reproducibility in the range of 1.52–5.27% in extracting the five target analytes. In addition, the intra-day and inter-day precision values were found to be in the range of 0.78–6.86% and 1.66–8.41%, respectively. Finally, the proposed ATP/Fe 3 O 4 /PANI-based MDSPE method was successfully applied to analyze river water samples by rapid preconcentration of BUs.
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ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2017
·
IF 3.743
Xiaofeng Yi,Jiarui He,Yingyuan Guo,Zhenhua Han,Meixia Yang,Jiali Jin,Junjie Gu,Minrui Ou,Xiaoping Xu
The aim of this work was to study the removal of Cu (II) and U (VI) ions from aqueous solutions by encapsulating magnetic Fe 3 O 4 nanoparticles into calcium alginate coated chitosan hydrochloride (CCM) hydrogel beads. ATR-FTIR and XRD analysis data indicated that the CCM composites were successfully prepared. SEM images and EDX spectra showed that Cu 2+ and UO 2 2+ ions were adhered onto sorbents . Adsorption properties for removal of both copper and uranium ions under various experimental conditions were investigated. Kinetic data and sorption equilibrium isotherms were also conducted in batch process . The sorption kinetic analysis revealed that sorption of Cu (II) and U (VI) followed the pseudo-second-order model well and exhibited 3-stage intraparticle diffusion model during the whole sorption process. Equilibrium data were best described by Langmuir model, and the CCM composite hydrogel beads showed the estimated maximum adsorption capacity 143.276 mg/g and 392.692 mg/g for Cu (II) and U (VI), respectively. The CCM adsorbent exhibited excellent reusability for five cycles use without significant changes in the adsorption capacity and structural stability. The results demonstrated that CCM can be an effective and promising sorbent for Cu (II) and U (VI) ions in wastewater.
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ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Yang Yang,Jiaqi Li,Dingqiong Chen,Jinbao Zhao
Fe3O4 is regarded as an attractive anode material for lithium ion batteries (LIBs) due to its high theoretical capacity, natural abundance, and low cost. However, the poor cyclic performance resulting from the low conductivity and huge volume change during cycling impedes its application. Here we have developed a facile electrophoretic deposition route to fabricate the Fe3O4/CNTs (carbon nanotubes)/rGO (reduced graphene oxide) composite electrode, simultaneously achieving material synthesis and electrode assembling. Even without binders, the adhesion and mechanical firmness of the electrode are strong enough to be used for LIB anode. In this specific structure, Fe3O4 nanoparticles (NPs) interconnected by CNTs are sandwiched by rGO layers to form a robust network with good conductivity. The resulting Fe3O4/CNTs/rGO composite electrode exhibits much improved electrochemical performance (high reversible capacity of 540 mAh g–1 at a very high current density of 10 A g–1, and a remarkable capacity of 1080 mAh g–1 can be maintained after 450 cycles at 1 A g–1) compared with that of commercial Fe3O4 NPs electrode.
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JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 53
·期 3
·1945-1961
·
IF 2.599
Xu Jing-Wen,Cui Zhuo-Miao,Xu Feng,Luo Yan-Ling
Multi-component block copolymer nanohybrids consisting of Fe 3 O 4 nanoparticles and poly(acryloyloxyethyloxyl 1-mercaptohemisuccinate) and poly(methacrylic acid) (PMAA) blocks were synthesized via the surface-initiated atom transfer radical polymerization, followed by the esterification with d,l-mercaptosuccinic acid. The block copolymer nanohybrids were coordinated with Au nanoparticles (Au NPs) through pendent thiol groups to form Au NPs coordinated Fe 3 O 4 graft block copolymer nanohybrids. Fluorescent spectrometry, TEM and SEM findings indicated that these block copolymer nanohybrids could self-assembled and form globular core–shell nanomicelles, and their critical micelle concentrations decreased with the decrease in the length of PMAA chains and the incorporation of Au NPs. Zeta potential measurements signified that the copolymer nanohybrids possessed significantly high stability. DLS results indicated that hydrodynamic diameters of the copolymer nanohybrids distributed within the scope of 85–155 nm, hinging on the length of the graft chains and the complexation of Au NPs. The hybrid block copolymer nanomicelles exhibited pH, electrochemical and magnetic responsiveness, with pH transition points at 5.3–5.9. The incorporation and the loading percentage of Au NPs improved the reversibility of the electrochemical response and plasmon resonance. The block copolymer nanohybrids were superparamagnetic and were expected to broaden their applications by virtue of the multi-component combination and the resulting multifunctionality.
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NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 18
·10155-10164
·
IF 3.269
Weijun Fang,Hanyuan Zhang,Xin Wang,Wenmei Wei,Yujun Shen,Jishuang Yu,Junxing Liang,Jun Zheng,Yuxian Shen
Multidrug-resistant (MDR) bacterial strains have emerged because of the widespread overuse of antibiotics. Thus, the development of new antibacterial materials and therapeutic methods to effectively kill bacteria is essential. A new type of silver core/magnetic Fe3O4 shell nanoparticle with strong magnetic responsiveness and tunable plasmonic properties (480–825 nm) has been developed as a multifunctional platform for bacterial disinfection. In this study, we firstly demonstrate that these Ag@Fe3O4–PEI NPs can be used as effective photothermal agents for simultaneous capture and photothermal killing of bacterial pathogens. Owing to the perfect combination of magnetic and photothermal properties in a single particle, the as-prepared Ag@Fe3O4–PEI NPs exhibit not only a wide range of bacterial capture abilities via electrostatic interaction between the positively charged magnetic Fe3O4 shell and the negatively charged bacterial cell wall but also outstanding photothermal antibacterial activity under NIR irradiation. The photothermal antibacterial tests show that even a concentration of 25 ppm of nanoparticles is enough to kill 100% of E. coli BL21 (107 CFU mL−1) in 10 min upon NIR irradiation. Furthermore, the Ag@Fe3O4–PEI NPs also show excellent photothermal stability, high magnetic recyclability, and low cytotoxicity. Therefore, we believe that these unique advantages make the as-prepared multifunctional core–shell nanocomposites very promising for biomedical sterilization applications.
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